Ideal MHD operational limits for highly elongated tokamaks
The construction of strongly shaped and elongated tokamaks is to a large extent motivated by the theoretical prediction that the beta-limit is proportional to the plasma current. Experimental results confirm the advantageous effects of increased elongation (beta = 11 % was reached with an elongation kappa = 2.34 in DIII-D). The understanding of beta and other operational limits at very high elongation (kappa greater than 2.5) is, however, very limited. Notably, it is not clear whether the beta limit can be further increased by an increase in kappa or by other types of shaping, whether vertical stability limits the achievable elongation and whether control of current and pressure profiles is necessary. This paper reports on an ideal MHD stability study, with the aim of clarifying the operational limits imposed by n = 0 (vertical), 1 (kink) and infinity (ballooning) stability for tokamaks with elongation from 2 to 3, with particular emphasis on shapes accessible to the TCV tokamak in Lausanne.
Bibliographic Reference: Article: Proceedings of the 19th EPS Conference on Controlled Fusion and Plasma Physics - Contributed Papers, Part 1, Vol. 16C (1992)
Record Number: 199211567 / Last updated on: 1994-11-29
Original language: en
Available languages: en